Case study:Biotop and flood measures in the Mykle river (Mykleelva) and Vanebu river (Vanebuelva)
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- 1 Project overview
- 2 Image gallery
- 3 Catchment and subcatchment
- 4 Site
- 5 Project background
- 6 Reasons for river restoration
- 7 Measures
- 8 Monitoring
- 9 Additional documents and videos
- 10 Additional links and references
- 11 Supplementary Information
|Project web site||http://www.vannportalen.no/globalassets/vannregioner/vest-viken/vest-viken---dokumenter/vannomrader-i-vest-viken/siljan-farris/dokumenter/fagrapporter/biotop--og-flomtiltak-i-mykleelva-og-vanebuelva_rapport.pdf|
|Themes||Environmental flows and water resources, Flood risk management, Habitat and biodiversity, Hydropower, Hydromorphology|
|Main contact forename||Steinar|
|Main contact surname||Bergan Tronhus|
|Main contact user ID|
|Contact organisation||Water District (Vannområde) Siljan - Farris|
|Contact organisation web site||http://http://www.vannportalen.no/vannregioner/vestviken/vannomraader/siljan-farris/|
|Partner organisations||Skagerak Kraft AS, University of South-Eastern Norway (USN)|
|Parent multi-site project|
| This is a parent project
encompassing the following
Mykleelva and Vanebuelva are part of the same river system, separated by two small lakes. They are regarded as heavily modified water bodies (HMWB) because the flow regime is regulated for hydropower. The reason for carrying out habitat improvements was because the water bodies have no requirements for minimum water flow. This results in very low water flows during periods of the year.
In this project, an improved thalweg (line of fastest flow and deepest water) and ponds were made at several locations along the rivers. These maintain greater habitat stability and connectivity during low flows. A new road and bridge across the river were also built as flood measures.
Monitoring surveys and results
It took some time for the measures to be implemented, but eventually they were carried out as planned. It will take time for the expected ecological improvements to happen. The new pool and running water areas will undergo recolonization and adaptation.
The effect of such measures can be difficult to measure, but there is little doubt that more stable water flow, larger and deeper pools and concentration of water flow will benefit the ecosystems in and around the rivers.
Thus far, the rivers have only achieved moderate ecology potential and further measures are needed to raise their ecological status further. As the water bodies are HMWBs, they will never reach full good ecological status, but with further restoration measures Mykleelva and Vanebuelva can achieve good ecological potential.
The improvement works will require maintenance as their “life expectancy” depends on the amount of river sediment transport and the frequency and magnitude of the floods.
Catchment and subcatchment
Cost for project phases
Reasons for river restoration
Hydromorphological quality elements
Biological quality elements
Physico-chemical quality elements
Additional documents and videos